Alguém tentou usar transações no .NetCore? Eu tentei e não consigo fazê-lo funcionar corretamente.

Minha configuração:

Mongo4 (conjunto de réplicas de 3 nós)Visual Studio 2017MongoDB.Driver 2.7.0.Net Core 2.0. Aplicação de console

Estou seguindo as instruções:https://docs.mongodb.com/manual/core/transactions/

O problema é que o novo documento é criado no banco de dados toda vez (se eu abortar uma transação, se eu confirmar uma transação, ...)

Também tentei usar transações diretamente no banco de dados e elas funcionam, também tentei com o NodeJS e elas também funcionam. Talvez haja um erro no driver, não sei o que estou fazendo de errado.

Código:

using System;
using MongoDB.Bson;
using MongoDB.Driver;

namespace ConsoleApp2
{
    class Program
    {
        static void Main(string[] args)
        {
            var connString = "mongodb://user:password@localhost:27017";
            var client = new MongoClient(connString);

            using (var session = client.StartSession())
            {
                try
                {
                    RunTransactionWithRetry(UpdateEmployeeInfo, client, session);
                }
                catch (Exception exception)
                {
                    // do something with error
                    Console.WriteLine($"Non transient exception caught during transaction: ${exception.Message}.");
                }
            }

        }

        public static void RunTransactionWithRetry(Action<IMongoClient, IClientSessionHandle> txnFunc, IMongoClient client, IClientSessionHandle session)
        {
            while (true)
            {
                try
                {
                    txnFunc(client, session); // performs transaction
                    break;
                }
                catch (MongoException exception)
                {
                    // if transient error, retry the whole transaction
                    if (exception.HasErrorLabel("TransientTransactionError"))
                    {
                        Console.WriteLine("TransientTransactionError, retrying transaction.");
                        continue;
                    }
                    else
                    {
                        throw;
                    }
                }
            }
        }

        public static void CommitWithRetry(IClientSessionHandle session)
        {
            while (true)
            {
                try
                {
                    session.CommitTransaction();
                    Console.WriteLine("Transaction committed.");
                    break;
                }
                catch (MongoException exception)
                {
                    // can retry commit
                    if (exception.HasErrorLabel("UnknownTransactionCommitResult"))
                    {
                        Console.WriteLine("UnknwonTransactionCommiResult, retrying commit operation");
                        continue;
                    }
                    else
                    {
                        Console.WriteLine($"Error during commit: {exception.Message}.");
                        throw;
                    }
                }
            }
        }

        // updates two collections in a transaction
        public static void UpdateEmployeeInfo(IMongoClient client, IClientSessionHandle session)
        {
            var employeesCollection = client.GetDatabase("testdatabase").GetCollection<BsonDocument>("employees");
            var eventsCollection = client.GetDatabase("testdatabase").GetCollection<BsonDocument>("events");

            session.StartTransaction(new TransactionOptions(
                readConcern: ReadConcern.Snapshot,
                writeConcern: WriteConcern.WMajority));

            try
            {
                employeesCollection.UpdateOne(
                    Builders<BsonDocument>.Filter.Eq("employee", 3),
                    Builders<BsonDocument>.Update.Set("status", "Inactive"));
                eventsCollection.InsertOne(
                    new BsonDocument
                    {
                { "employee", 3 },
                { "status", new BsonDocument { { "new", "Inactive" }, { "old", "Active" } } }
                    });
            }
            catch (Exception exception)
            {
                Console.WriteLine($"Caught exception during transaction, aborting: {exception.Message}.");
                session.AbortTransaction();
                throw;
            }

            //I WANT TO ABORT TRANSACTION - BUT THE RECORD "employee:3...." IS STILL IN DATABASE "events"
            session.AbortTransaction();
        }

        public static void UpdateEmployeeInfoWithTransactionRetry(IMongoClient client)
        {
            // start a session
            using (var session = client.StartSession())
            {
                try
                {
                    RunTransactionWithRetry(UpdateEmployeeInfo, client, session);
                }
                catch (Exception exception)
                {
                    // do something with error
                    Console.WriteLine($"Non transient exception caught during transaction: ${exception.Message}.");
                }
            }
        }
    }
}